Tayshall,
There are numerous great meeting spots on the Adventure, but the time, interests and purpose make a difference in what I might suggest. How many people? Right when everyone gets onboard or later in the day/evening? Since most people head right for the buffet at the Windjammer/Island Grill when they get onboard the aft (outside) portion of the The Island Grill is good. But, the pool bar on deck 11 is great, if weather permits. The Viking Crown Lounge on Deck 13 is another good spot.
Nancy

We're just looking for a meeting place for the first day when all of us have arrived on the ship. I would say that everyone should be onboard by 5:00 pm. and because I have never sailed on this particular ship before I'm not able to give everyone a meeting place. But, your suggestion of The Viking Crown Lounge on Deck 13 sounds good. Thanks for your suggestion. If you have any others let me know.